I have a few mods on my 400ex...440 big bore,stage 2 hot cam,HMF exhaust. I am sure its running lean. Jet in it is a 152 and I know it will take larger. Any suggestions on where to start as for jetting larger and possible kit to look for??? Thanks

 

what kind of jet are you running ? i have a 07 400ex with ehs airbox lid twin air filter and carb spacer & hmf slippie. i run 170 dyno jet. i am 565 above sea level.

 

152?!?!?! Ya, way lean I wouldn't ride it much with a 152. It's not getting enough fuel to take advantage of your mods. Start with 170 if you run with lid off. Maybe 160 with lid on. And I'd just get single jets, mucho cheaper than a kit.

 

it is cheaper to buy single jets but if you have a 05 or up dyno jet gives you a tool for the fuel mixture screw.

 

You can call dynojet and they will let you order just the mixture screw if you need it.

 

I will definitely give that info a go. Thanks, I will post the results after I do the mods and give it a run.